The present invention relates to the art of automotive vehicle snowplows and accessories and controls therefor, and more particularly to a manual switching unit adapted to provide a digital control signal to the vehicle DC power bus in the passenger compartment and an operating unit in the engine compartment adapted to control a snowplow or other vehicle accessory according to the digital signal.
The invention finds particular utility in connection with a snowplow and control system of the type disclosed in U.S. Pat. Nos. 3,706,144 to Miceli and U.S. Pat. No. 5,361,519 to Ciula, et al., owned by the assignee of the present invention and the disclosures of which are hereby incorporated herein by reference. Accordingly, the invention will be disclosed and described in detail herein in conjunction with a plow and control system according to the Miceli and Ciula patents. It will be appreciated, however, that the present invention can be applied to other accessories and control system configurations.
In a snowplow and control system arrangement of the type disclosed in the Miceli patent, the snowplow blade is mounted on the front of a vehicle along with hydraulic cylinders by which the blade is raised and lowered with respect to the vehicle and by which the blade is angled or pivoted left or right relative to the vehicle. The plow control system further includes solenoid operated valves by which the flow of hydraulic fluid to and from the cylinders is controlled. Positioning of the plow blade through control of the solenoid valves and an electric motor driven hydraulic pump in the system is achieved through a control device mounted in the vehicle passenger compartment for operation by the vehicle operator. Additional controls are optionally provided for auxiliary lighting such as those shown in U.S. Pat. No. 5,832,637 to Aguado et al., the disclosure of which is incorporated herein by reference.
In the systems of the Miceli and Ciula patents, a multiple conductor cable harness extends from the vehicle passenger compartment to the engine compartment. A control device is mounted in the passenger compartment and provides electrical control signals through the cable harness to the solenoids and the electric motor, thereby achieving controlled positioning of the snowplow blade. In the Miceli patent, the control device includes a pair of pivotal operating switch levers having a neutral or hold position. The first lever is pivotal from its hold position to selectively raise or lower the blade and the second lever is pivotal from its hold position to selectively angle the snowplow blade left or right. In the Ciula patent, the control device includes individual momentary type electrical switchpad buttons for selectively operating the snowplow blade in the up, down, left, and right directions, which buttons are respectively labeled U, D, L, and R. In the Miceli patent, as well as many prior art systems, the control device is mounted in a single permanent location in the vehicle passenger compartment, whereas in the Ciula patent, the control device is relocatable inside the passenger compartment for operator comfort and ergonomic efficiency.
Heretofore, the cable harness connecting the passenger compartment control device with the engine compartment or external control solenoids and motor has been difficult and costly to install, requiring the installer to make a feed-through hole in the vehicle firewall. In addition, the routing length and path as well as the firewall hole location is different for different vehicles, thus requiring suppliers of such control systems to inventory numerous different cable harnesses and associated accessories. Furthermore, installation personnel heretofore were required to be knowledgeable in the specifics of the installation procedures for many different vehicle types. Moreover, maintaining and troubleshooting such a snowplow control system requires detailed knowledge as well as routing and wiring schematics for the specific vehicle type. The foregoing problems are compounded in the common situation where the snowplow equipment is seasonally removed for storage during warm weather, and subsequently reinstalled onto the vehicle.
Other attempts have been made to address the above problems. In U.S. Pat. No. 5,524,368 to Struck et al., a wireless snowplow control system is disclosed, which uses a wireless radio remote control to control a vehicle-mounted snowplow. The Struck system, however, introduces additional safety problems associated with a wireless receiver picking up spurious noise, potentially creating risk of unintended personal or property injury. An additional problem associated with wireless systems, particularly apparent in garage door opener applications, is the need to provide user-settable transmitter and receiver addresses, to prevent unauthorized or unintended operation by the owner of an unrelated transmitter.